The broad category of data communication may be broken down into two general types of datastreams—frame datastreams (e.g., packet datastreams or cell datastreams) and continuous datastreams. A frame datastream is one in which provision is usually made to insert or delete non-data filler frames between valid data frames. The non-data filler packets enable minor variances in clock frequencies at the boundaries of a transport network to be accommodated by insertion and/or deletion of the non-data filler packets in the event of underflow and/or overflow. In contrast, a device processing a continuous datastream has no opportunity to insert or delete non-data filler packets for rate-matching purposes because such non-data filler packets do not exist. In a continuous datastream, every bit has meaning and nothing can be added or deleted from the datastream. Example continuous datastreams include FM radio broadcasts, analog voice, unencoded music, CD audio output, analog video, NTSC television broadcasts, and the like.
FIG. 1 illustrates transport of a continuous datastream (e.g., a video signal) across a wide area network (“WAN”) using conventional techniques (e.g., NTSC broadcasting, etc.), not a frame based (e.g., packet switching or cell switching) network. The continuous datastream may be transported across a frame based network, if partial loss by periodically deleting portions of the continuous datastream is acceptable. However, known techniques do not provide a mechanism to transport a complete continuous datastream without loss over a frame-based transport network.